When it comes to choosing the right food for your cat, ingredient quality matters. One of the most misunderstood components in many commercial cat foods is animal by-products. These ingredients are often broadly defined, inconsistently sourced, and can vary significantly in nutritional value. While some by-products may offer certain benefits, others raise concerns about digestibility, transparency, and species-appropriateness. 

Understanding what animal by-products really are and how they’re used in the pet food industry is essential for making informed decisions about your cat’s diet.

What Are Animal By-Products In Cat Food?

Animal by-products in cat food, which are also known as meat and animal derivatives, are ingredients that come from the bodies of animals which are not part of the human food chain. This can include a variety of organs and other parts of the animal left over after slaughtering. While some by‑products (like organ meats) are highly nutritious, others, such as rendered bones or feathers, contribute little more than indigestible material.

How Do Animal By-Products End Up In Cat Food?

Animal by‑products in cat food typically originate from the parts of slaughtered livestock that aren’t used for human consumption. This includes organs, bones, feathers, and other “offal.” After an animal is processed for meat, the leftover tissues are collected and rendered. This means they’re cooked at high temperatures to remove moisture and fat, then ground into a powder.

Renderers source these materials from slaughterhouses and poultry processors. Because it’s less expensive than whole‑muscle meat, pet food manufacturers blend by‑product meals into their recipes to boost protein content and lower costs.

What Are the Common Types Of By-Products Used In Cat Food?

Not all by-products are inherently bad. Organs like the liver can be highly nutritious. However, the lack of transparency, inconsistency in sourcing, and inclusion of low-value or indigestible materials are why many premium pet food brands choose to exclude by-products altogether. Here are the most common types of by-products found in cat food;

Why Are Animal By-Products Used By Some Cat Food Brands?

Animal by-products are used because they can be more sustainable as they utilise parts of the animal that might otherwise be discarded, reducing waste. Additionally, companies use animal by-products in cat food because it’s cheap, making it more affordable for pet parents with a tight budget. However, this does not make it high quality.

 

Do By-Products Have Any Nutritional Value?

Animal by-products can add certain nutritional value to your cat’s food, especially some organs. They are often rich in protein, vitamins, and minerals, and can be a valuable addition to your cat’s diet. However, some by-products like feathers can cause poor digestibility and offer little to no nutritional benefit, as they are not easily broken down or utilised by your cat’s body. Low-quality by-products may also lack the essential nutrients your cat needs, making them an unsuitable choice for species-appropriate nutrition.

How To Know If Cat Food Has Animal By-Products In It?

Examine the ingredient list on the packaging to determine whether the cat food contains animal byproducts. Certain phrases, like "meat by-products," "animal digest," or "animal by-product meal," are signs of by-products, so look for these. Think about whether these terms are near the beginning or the end of the ingredient list, and if they are there. Higher amounts of ingredients are found in those listed earlier in the list. 

Are “Meat Derivatives” Just Another Word for By-Products?

The phrase "meat derivatives" basically refers to meat by-products, particularly the portions of an animal carcass that are not normally consumed by humans. These can include bones, organs, and other tissues that are left over after the main meat pieces have been sliced. 

What Makes an Animal By-Product-Free Cat Food Different?

An animal by-product-free cat food is different because it contains only clearly identified, high-quality animal ingredients like named cuts of meat, fish, or poultry, without the use of vague or rendered parts like "meat by-product" or "animal digest." Instead of relying on low-cost fillers made from leftover animal parts, these formulas prioritise whole muscle meats and organs from traceable sources, ensuring a more consistent nutritional profile.

This type of cat food often reflects a higher standard of transparency and ingredient integrity. Every component is typically listed in detail, allowing cat owners to know exactly what their cat is eating. 

Beyond the ingredient list, by-product-free cat food is usually formulated with digestibility, bioavailability, and long-term health in mind. Cats are obligate carnivores, so the quality of their protein matters. By avoiding rendered waste and sticking to purposeful, species-appropriate ingredients, these foods aim to support healthy skin, coat, energy levels, and digestion, without the risks or unknowns associated with animal by-products.

Do Cats Still Get All The Nutrients Without Animal By-Products?

Cats can get all the nutrients they need without the inclusion of animal by-products, which can cause more harm than good, provided their food is formulated to deliver complete and balanced nutrition. Essential vitamins, minerals, and proteins can be sourced from clearly identified, high-quality ingredients such as whole meats, specific organ meats, and targeted supplements, ensuring every component serves a genuine nutritional purpose without relying on mystery or low-value additives.

Are There Any Health Benefits of Avoiding Animal By-Products In Cat Food?

Avoiding animal by-products in cat food can offer several potential health benefits, especially when the food is made with high-quality, named ingredients. One key benefit is improved digestibility; cats may find it easier to process whole cuts of meat and clearly defined organ ingredients compared to low-grade, rendered by-products that can contain indigestible materials like bone fragments or feathers.

Another advantage is reduced risk of food sensitivities or allergies. Since by-products often include a mix of unidentified animal parts and species, they can trigger reactions in sensitive cats. 

Not all by-products are harmful, but the lack of clarity around what they contain makes it difficult for pet owners to trust them. Choosing a cat food made without animal by-products allows for greater confidence in the ingredients you’re feeding your cat. With clear labelling, high-quality protein sources, and nutrition backed by science, by-product-free formulas give your cat everything they need, without the unknowns. For pet parents who value transparency and quality, steering clear of animal by-products is a simple step toward better feline health and well-being.